How to read the state of a 7 segment display

[ChrisGreece52]

Regarding digital clocks and 4000 series CMOS, which may have some helpful insights, I guess you've seen this?

Thats where i got the idea!

[ChrisGreece52]

Cheating?

Me? 

I learned tricks like using EPROMs as programmable logic from an expert, a guy who could look at a PC card and tell you what each chip did without even a schematic or a block diagram. This was a man who used EPROMs as frequency dividers and 16:1 multiplexors as 16 bit memories, the guy was a wizard of logic.

I would not like to your EPROMs because i dont have the knowledge im an electronics engineering at my second year and  we just now got to learn about Boolean algebra .... i dont consider myself to be in a hobbyist level but i am not a pro ... so yeah ill stick with simple stuff for now

[ChrisGreece52]

"ms" = milliseconds?  The numbers will fly around so fast you can't see them!

No. Leap years happen every 4 years. You cannot determine leap year by simply looking at the unit's digit.
There are even more rules than that, but it seems unlikely that your clock will still be running when the next exception occurs (in 2100)
You could have looked up:  https://en.wikipedia.org/wiki/Leap_year#Algorithm


Sorry, that just does not make any sense.  You already HAVE the BCD digit to feed INTO the 4511.
Why on earth do you think you must DECODE the 7-segment levels to recover the BCD digit. Makes zero sense.


Can you explain to us WHY you want to construct a clock circuit like this? This method has not been practical since perhaps before you were born.
A 555 timer chip is completely impractical as a timing source for any kind of clock.
And, unless you use an above-average crystal oscillator (or one made specifically for clocks), it will also have significant drift.


What do you mean "analog circuitry"?  Nothing you have been discussing is "analog" in any sense of the word.  This is really confusing.

1) No problem for the ms numbers flying so fast i think it would be a nice addition
2)I got the wrong information from a random website so my mistake there
3)I thought that if i wanted to get info for the leap year (which in my mind was 2 years) i needed to see when the last digit output was 0.2.4.6.8 so i could add another day on February ... now i think the best solution would be a counter that i use to count to 4 for the leap year
4)I was not thinking of implementing the 555 into the final design but rather using it for testing the final design will have a crystal oscillator and a divider to get the 1kHz frequency to drive ms and then another devider to get a 1Hz frequency for the seconds.

Hope i covered your answers and i am sorry for the poor explaining i did .